Most people acquire information with eyes. Once something happen for vision of eye, such as myopia, presbyopic, hyperopia and/or astigmatism, the vision correction is implemented by laser surgery. However, wearing a pair of eyeglasses with specific diopter is popular for most people.
There are various purposes for eyeglasses on market, such as optical eyeglasses, sunglasses, sports glasses or protective eyewear, and so on. Furthermore, lenses for eyeglasses can be divided into nearsighted lens or presbyopic lens, etc. Generally, once user's vision or eye situation changes, such as nearsighted, farsighted or astigmatism diopter increases, user often replace whole pair of wearing eyeglasses that meets user's requirement no longer and possibly causes eye fatigue. However, cost of eyeglasses replacement can cause a burden on user. Furthermore, owning plural pairs of eyeglasses of different diopters or functions is not convenient to user and cause another burden on user, too.